Lifting-magnet.



PATBNTED DEC. 13

S. PIEK.

LIFTING MAGNET.

APPLICATION FILED 0019,1903.

N0 MODEL.

m. r. w m I PATENTED DEC. 13, 1904.

S. PIEK. LIFTING MAGNET.

APPLIGATION FILED OCT. 9, 1903.

4 SHEETS-SHEET 2.

no MODEL.

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PATENTED DEC. 13

s. PIEK. LIPTING MAGNET.

APPLICATION FILED OCTv 9, 1903.

4 SHEETS-SHEET 3,

' N0 MODEL.

NI). 777,221. PATENTED DEC. 13, 1904.

s. PIEK.

LIPTING MAGNET.

APPLICATION FILED OUT. 9, 1903.

N0 MODEL. 4 SHEETSSHEBT 4.

wilivmoaaq Mqbm I fl W. m (MJMM Patented December 13, 1904.

PATENT OFFICE.

STEPHEN PIEK, OF BUFFALO, NEW YORK.

LlFTING-MAGNET.

SPECIFICATION forming part of Letters Patent No. 777,221, dated December 13, 1904.

Application filed October 9, 1908.

To all whom, it may concern.-

Be it known that I, STEPHEN PIEK, a resident of Buffalo, in the county of Erie and State of New York, (post-office address 182 Norwood avenue,) have invented a new and useful 11nprovementin Lifting-Magnets; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to magnets for lifting metallic articles; and the object of my invention is to provide a powerful magnet for this purpose which is provided with movable polepieces to engage articles having irregular surfaces or a series of differently sized or placed articles, such as pig-iron, and which is provided with specially arranged ventilating means to keep the same cool.

The invention also comprises details of construction, which will be hereinafter described and claimed.

In the accompanying drawings, Figure l is a vertical section through my magnet. Fig. 2 is a plan view of the same, showing the covered plate broken away on one-half. Fig. 3 is an inverted plan View showing on one-third portion the outside bottom plate, on another third portion said plate broken away, and on another third portion both the outside and inside bottom plates broken away. Fig. 4 is a plan of the means for separating the coils. Fig. 5 is a vertical section, on an enlarged scale, on the line 5 5, Fig. 41:. Fig. 6 is an edge view of a portion thereof, and Fig. 7 is a side view of one of the binding-posts.

The frame or casing 1 of the magnet is made of magnetic material, preferably soft caststeel, and is provided with the outside annular shell 2 and the central projection 3, which are joined at the top by suitable metallic connections 4,.leaving'spaces 5 between said connections to provide for ventilation. The parts 2, 3, and 4 might be made in separate pieces suitably united; but preferably they will be cast as one integral piece. The coil or coils 6 are placed in the annular chamber 5 between the external shell 2 and the central projection 3. Preferably a plurality of separate coils will be employed, four such coils being shown and these being connected in series and joined, by means of leading wires 7 and 8, to the brass Serial No. 176,398. (No model.)

connecting-pieces or binding-posts 9, to which are also connected the positive and negative mains 10 and 11.

The coils rest upon an inside bottom plate 13, which is of annular form and closes the bottom of the annular chamber 5. This plate is provided with openings or slots 1 to permit of the ventilation of the coils and rests upon the outside bottom plate 15, which also is of annular shape and provided with openings or slots 16. The outside plate is secured to the external annular shell 2 by means of bolts 17 and spacing-sleeves 18 and is secured to the central projection 3 by means of tapbolts 19. Preferably the inside bottom plate 13, outside bottom plate 15, and the spacingsleeves 18 will be formed of brass or other nonmagnetic material.

In a powerful magnet of this kind a large amount of heat is necessarily generated by the strong current passing through the coils. Consequently I construct my coils so that they can be thoroughly ventilated. Instead, therefore, of using only a single coil I prefer to use a plurality thereof, as described, although as they are connected in series they are practically one coil. In winding these coils rods 20, of fiber or other insulating material, are placed between the windings thereof and are wound in tightly by the outer windings of the coils. These rods hold different layers of the coils apart, thus forming vertical openings or passages through the coils. The several coils also are separated from each other by means of radial bars or spokes 21 of fiber or other insulating material. These radial bars or spokes are connected at their inner and outer ends to annular rings 22 and 23, being secured to said rings in any suitable way, such as providing their ends with slots 23, into which the rings fit, and being secured to said rings by means of the copper rivets 24 or other suitable fastening means. By this construction the several coils are separated from each other by an open or skeleton frame, and said coils are also provided with vertical openings therethrough. As a consequence the air can pass through the openings in the bottom plates and through the side openings in the casing and will circulate through the coils,

passing out through the openings 5 in the top of the frame or casing.

The magnet is covered by means of a top metallic plate 26, which is of annular shape, as shown, and provided with downturned flanges 27 at its inner and outer edges. This plate is secured by tap-bolts 28-to projections or studs 29, so that it is supported slightly above the casing or frame 1, thus permitting the entrance of air to or the escape of air from the openings 5 in the top of the frame.

As is well known in devices of this kind, the articles to be lifted form a part of the magnetic circuit, and the less magnetic resistance this circuit has to overcome the greater will be the pull or lift of the magnet, this pull being directly proportional to the square of the density of the magnetic flux. A magnet having a number of movable pole-pieces excited by one coil complies with these conditions, the movable pole-pieces reducing the air-gap considerably, and the single exciting coil makes it possible to increase the density of the magnetic fiux to almost saturation without an appreciable loss in the body of the magnet. Preferably a plurality of polepieces will be used both at the center of the magnet and also at the outside thereof. These movable pole-pieces may be arranged in a variety of ways, and in the drawings I have shown the central projection 3 provided with a plurality of vertical openings for receiving a similar number of vertically-movable steel pole-pieces 30, seven such pole-pieces being provided, although their number might be varied. In the same manner the outer annular shell 2 is provided with the projecting ring portion 31, which also is provided with a series of vertical openings in which are placed the vertically-movable pole-pieces 32. Both the internal and external pole-pieces are provided with enlargements or heads 33 at their upper ends, which will prevent them from falling out when the current is cut ofi from the coils. Various other arrangements, however, might be provided for preventing these pole-pieces from falling out. The outer bottom plate 15 is cut away on its inner edge, as at 34:, to provide space for the central polepieces 30.

In the use of my magnet it will be suspended in any convenient wayas, for instance, by the eyebolts 35 from the hook of a crane, derrick, or other lifting means. The magnet will be energized by closing the circuit through the coils 6, and this will set up a powerful magnetic field, the flux flowing approximately in the dotted lines 36that is, from the inner or central pole-pieces 30 outwardly through space to the outer pole-pieces 32 and thence up through the annular shell 2 and top connecting members 4 back to the central polepieces. The magnet is lowered down upon the article or articles to be lifted, the polepieces 30 and 32 readily moving upwardly greater or lesser distances and adapting themselves to the irregularities of the top surfaces of the body or bodies to be lifted. As a consequence these bodies will be in direct contact with the pole-pieces, thus being in the maximum strength of the magnetic field and also further attracted by the magnetic adhesion. As a result, a very powerful lifting action is secured, it being shown by actual test that this magnet will lift twice as many irregular metallic bodies, such as pig-iron, when the movable poles were used as when the movement of the poles is prevented.

A very strong current can be used with my magnet, since there is no dangerof overheating the same, this being effectively overcome by the thorough ventilation provided by spacing the coils apart and providing them with the vertical openings therethrough. This magnet has been found to be of especial value for handling pig-iron and the like, but obviously may be used for handling any metal lic body or bodies, whether provided with irregular faces or with regular or even faces.

I am of course aware that lifting-magnets have heretofore been provided with a plurality of movable pole-pieces; but in all such prior magnets each pole-piece was provided with a separate magnetic coil, this being a decided disadvantage, as it tended to dissipate the magnetic field. With my magnet, however, there is practically only one coil, and a plurality of movable pole-pieces are in the field of this single coil. As a consequence, the lines of magnetic fiux are not disturbed in any way by the proximity thereto of lines of force created by another magnet, so that the density of the magnetic flux can be increased almost to saturation.

What I claim is 1. In a lifting-magnet, the combination of a single magnet-coil arranged with its windings horizontal, and a plurality of pole-pieces in the field of said coil and movable at right angles to the windings of said coil.

2. In a lifting-magnet, the combination of a frame, means for suspending the same, a solenoid-coil secured to said frame and arranged with its bore vertical, and a coremovably arranged in the bore of said solenoidcoil.

3. In a lifting-magnet, the combination of a solenoid-coil arranged with its bore vertical, and a plurality of cores movably mounted in the bore of said coil.

4:. In a lifting-magnet, the combination of a magnet-coil, a movable pole-piece arranged centrally within said coil, and a movable polepiece outside of said coil.

5. In a lifting-magnet, the combination of a magnet-coil, a movable pole-piece arranged centrally within said coil, and a plurality of movable pole-pieces surrounding said coil.

6. In a lifting-magnet, the combination of a magnet-coil, a plurality of movable polepieces within said coil, and a plurality of movable pole-pieces surrounding said coil.

7. In a lifting-magnet, the combination of a frame, means for suspending the same, a magnet-coil secured to said frame, a central pole-piece therefor, and an annular series of pole-pieces surrounding said coil.

8. In a lifting-magnet, the combination of a frame or casing having a central projection and an external shell, a coil in the annular chamber between said shell and central projection, movable pole-pieces in said central projection, and a series of movable pole-pieces on said external shell.

9. In a lifting-magnet, the combination of a frame or casing provided with a central portion and an external annular shell, metallic connections at the top of said shell and central portion, a coil in the annular chamber between said shell and central portion, vertical openings in said shell and central portion, and pole-pieces movably mounted in said openings.

10. In a lifting-magnet, the combination of the frame or shell, a plurality of coils therein, radial spacing-bars separating said coils, and pole-pieces on said frame.

11. In a lifting-magnet, the combination of the frame or shell, of a plurality of coils therein, skeleton frames separating said coils, and movable pole-pieces for said coils.

12. In a lifting-magnet, the combination of a frame or shell, a plurality of coils therein, and separating-frames between said coils, said frames comprising annular rings and radial bars of non-conducting material connected thereto.

13. In a lifting-magnet, the combination of the frame or shell, a coil therein, the windings of said coil being separated by bars of non-conducting material, and movable polepieces on said frame.

14:. In a lifting-magnet, the combination of the frame or shell, of a plurality of coils therein, said coils having their windings separated by bars of non-conducting material, and radially-arranged bars of non-conducting material separating said coils.

15. In a lifting-magnet, the combination of a frame or shell having openings in its top and bottom, a plurality of horizontally-arranged coils therein, skeleton frames separating said coils, vertical openings formed in said coils, and a cover-plate supported over the top of said frame.

16. In a lifting-magnet, the combination of a frame or casing provided with a central portion and an annular shell, metallic connections at the top of said shell and central portion so arranged as to provide openings therethrough, a coil in the annular chamber between said shell and central portion and provided with ventilating passages or openings, and a perforated plate of non-magnetic material closing the lower end of said annular chamber.

In testimony whereof I, the said STEPHEN PIEK, have hereunto set my hand.

S. PIEK.

liVitnesses:

C. C. SNYDER, J. O. HANNA. 

